1. Field of the Invention
This invention relates to a needle-less apparatus and method for blood sampling from a mammal, and in particular, to a fluid jet blood sampling system and method for obtaining a blood sample in which a jet of pressurized fluid penetrates the skin of a mammal, thereby allowing a blood sample to be taken from the mammal. More particularly, the invention relates to a compact, needle-less, fluid jet blood sampling system and method for obtaining a blood sample from a human patient, wherein the blood sampling device includes a disposable jet nozzle.
2. Background of the Related Art
Biological and biochemical analysis and testing of patients' blood is routinely performed to provide a vast array of diagnostic information concerning a patient's state of health. Consequently, blood sampling is an everyday occurrence in literally millions of medical establishments world-wide. In addition, blood sampling is also a commonly performed procedure in veterinary medicine and biomedical research.
Conventional blood sampling devices and methods involve perforating the skin of a patient with a lancet, a needle, or other sharp mechanical instrument (sharps). Needles, lancets, and the like will easily penetrate human skin as a result of accidental or casual contact with such sharps. In recent years there has been increasing concern over the risk to medical professionals of contracting serious blood-borne diseases (e.g. AIDS) by being accidentally cut or poked by sharps bearing contaminated (infectious) blood. There is also concern over similar risks to janitorial/disposal personnel who may be exposed to contaminated sharps in laboratory or hospital waste, and to members of the public who may be exposed to contaminated sharps which may have been improperly disposed of.
A number of attempts have been made to provide a blood sampling apparatus and/or method which produces perforation of the skin without the use of sharps. For example, U.S. Pat. No. 5,165,418 to Tankovich and U.S. Pat. No. 5,554,153 to Costello both disclose the use of laser devices for perforating the skin to permit blood samples to be drawn. Such devices, comprising a laser, are prone to be relatively bulky, immobile, and expensive.
Fluid jet technology has been used for various surgical procedures, such as for cutting tissue, penetrating the skin, and injecting substances into the body of a patient.
For example, U.S. Pat. No. 4,560,373 discloses a surgical nozzle apparatus for performing operations such as dissection, resection, and cutting by means of a jet of fluid. The apparatus includes a handpiece incorporating a nozzle piece for injecting a fluid under controlled pressure from a source of pressurized fluid, a valve assembly adapted to cut off the supply of the pressurized fluid to the nozzle piece, and a suction nozzle including a suction pipe connected to external suction means. U.S. Pat. No. 5,505,697 discloses an improved fluid jet injection method and device for piercing the skin and for injecting a substance into a patient. The device includes a plunger driver which impacts against a plunger to generate a high initial pressure pulse for piercing the skin. A lower delivery phase pressure is used during injection of the substance. U.S. Pat. No. 5,505,729 discloses a process and arrangement for high pressure fluid jet selective cutting of tissue, in which improved cutting speed is achieved, concomitant with minimal bleeding of the tissue by use of a high frequency electro-coagulator in combination with prior art liquid jet surgical cutting. U.S. Pat. No. 5,599,302 discloses a needle-less injection system which includes a portable, hand-held device for injecting a medical product into a patient, the device having a nozzle assembly. The injection system of the '302 patent includes an energy device for pushing the medical product out of the nozzle assembly, and an energy device actuating mechanism. The energy device is a self-contained gas spring operatively connected to a plunger. U.S. Pat. No. 5,562,692 discloses a pulsed fluid jet surgical tissue cutting/emulsifying and aspirating tool, in which a pressure intensifier piston arrangement functions in conjunction with a relatively low pressure fluid supply, a relatively low pressure gas supply, and a relatively high pressure relief valve, to pump a fluid jet as a series of high pressure pulses. The contents of U.S. Pat. Nos. 4,560,373, 5,505,697, 5,505,729, 5,599,302, and U.S. Pat. No. 5,562,692 are incorporated by reference herein in their entirety.
The possible use of a hydraulic jet or a high pressure jet of fluid has been disclosed in the context of methods to increase the permeability of the skin. For example, U.S. Pat. No. 5,445,611 to Eppstein et al. discloses methods for enhancing the permeability of the skin, with particular reference to the outermost layer of the skin (stratum corneum), to a permeant, drug, or pigment by the use of ultrasound, for the purpose of promoting uptake of substances into the skin or through the skin. The '611 patent mentions the use of a hydraulic jet as one of several possible mechanisms for perforating the skin in order to augment ultrasound induced increased skin permeability. However, the '611 patent does not teach the removal of a sample of blood, nor the removal of any other bodily fluid, molecules, cells, or tissue, from the body. U.S. Pat. No. 5,458,140 also to Eppstein et al., discloses methods for enhancing the permeability of the skin or mucosa (mucous membranes) to an analyte by the use of ultrasound, with or without the presence of a chemical enhancer, for the purposes of monitoring the analyte. The '140 patent mentions the use of a hydraulic jet as one of several possible mechanisms to form perforations in the stratum corneum in order to augment ultrasound induced enhanced skin permeability. However, the '140 patent does not teach the use of a fluid jet device as a means for forming a hole in the skin of an individual such as to permit the drawing of blood from that individual. Further, the '140 patent does not teach a method for obtaining blood from an individual. Nor does the '140 patent disclose an apparatus or method for forming a hole in the skin of an individual of sufficient width and/or depth to provide a quantity of blood; nor does the '140 patent disclose the collection of a blood sample from an individual, by means of a fluid jet, or otherwise.
The above references are incorporated by reference herein for their teachings of additional or alternative details, features and/or technical background.